Hard gelatin capsules are one of the most popular and commonly used dosage forms for the oral administration of drugs and supplements. They are easy to ingest and offer several advantages over other oral dosage forms such as tablets and powders.
How are they formulated and manufactured?
- Preparation of the gelatin dipping solution
The gelatin is dissolved in demineralized water, which has been heated to 60–70°C in jacketed pressure vessels and then cooled. It is then extracted and released for capsule manufacturing after the physical, chemical, and microbiological examination. The solution is then moved to temperature-controlled tanks on the dipping machine, where it is fed into the dipping dishes at a constant rate.
After that, capsule shells are produced in a controlled environment by dipping pairs (body and cap) of pre-stacked steel pins into an aqueous gelatin solution.
The bar with the pins is then removed and rotated many times to distribute the gelatin solution uniformly around them, ensuring reliable capsule wall thickness and dome strength.
The gelatin is then set on the mold using a blast of cold air. The gelatin is dried, and the pins are subsequently passed through several drying stages to reach the required moisture level.
Once the gelatin has been set and dried, the pins are trimmed to their final length, and any sharp edges are removed.
Once trimmed, the cap and body of the capsule are joined together using a special adhesive.
The capsules are then printed with relevant information, such as the batch number, expiry date, or manufacturer’s logo.
Now that you know how hard gelatin capsules are formulated and manufactured, you can be sure that the next time you take one, it is of the highest quality. Thanks for reading!